fix(compress): bound each Claude call with a timeout to stop indefinite hangs

subprocess.run([claude_bin, "--print"], ...) and the Anthropic SDK call in
call_claude() had no timeout, so a stalled claude CLI (dropped network, an
auth prompt with no TTY to answer it) blocked the caller forever instead of
failing into the existing retry loop. CLAUDE_CALL_TIMEOUT_SECONDS derives
from LOCK_WAIT_SECONDS / (MAX_RETRIES + 1), so the lock comment's claimed
worst-case bound is now actually enforced rather than assumed.